-al a-a a-b a-c aaa aab aac aae aaf aak aal ab- aba abb abc abe abf abk abl ac- aca acb acc ace acf ack acl aea aeb aec aee aef aek ael af- afa afb afc afe aff afk afl aka akb akc ake akk akl al- ala alb alc ale alf alk all baa bab bac bae baf bak bal bba bbb bbc bbe bbf bbk bbl bca bcb bcc bce bcf bck bcl be- bea beb bec bee bef bek bel bfa bfb bfc bfe bff bfl bka bkb bkc bke bkf bkk bkl bla blb blc ble blf blk bll c-- caa cab cac cae caf cak cal cba cbb cbc cbe cbf cbk cbl cca ccb ccc cce ccf cck ccl ce- cea ceb cec cee cef cek cel cfa cfb cfc cfe cff cfk cfl cka ckb ckc cl- cla clb clc cle clf clk cll eaa eab eac eae eaf eak eal eba ebb ebc ebe ebf ebk ebl ec- eca ecb ecc ece ecf eck ecl eea eeb eec eee eef eek eel ef- efa efb efc efe eff efl eka ekb ekc eke ekf ekl ela elb elc ele elf elk ell faa fab fac fae faf fak fal fba fbb fbc fbe fbf fbk fbl fca fcb fcc fce fcf fck fcl fea feb fec fee fef fek fel ffa ffc ffe fff ffk ffl fka fkb fkc fkf fkk fkl fla flb flc fle flf fll ka- kaa kab kac kae kaf kak kal kba kbb kbc kbe kbf kbk kbl kca kcb kcc kce kck kcl ke- kea keb kec kee kef kek kel kfa kfc kff kkb kkc kke kkk kkl kl- kla klb klc klf la- laa lab lac lae laf lak lal lba lbb lbc lbe lbf lbk lbl lca lcb lcc lce lcf lck lcl lea leb lec lee lef lek lel lfa lfb lfc lfe lff lfk lfl lka lkb lkl lla llb llc lle llf llk lll